tor_multipath_voip/src/algo_dup2.c
2019-08-13 10:58:20 +02:00

119 lines
3.7 KiB
C

#include "proxy.h"
#include "algo_utils.h"
#include "packet.h"
struct dup2_ctx {
uint16_t recv_id;
uint16_t emit_id;
};
void algo_dup2_init(struct evt_core_ctx* ctx, struct algo_ctx* app_ctx, struct algo_params* ap) {
app_ctx->misc = malloc(sizeof(struct dup2_ctx));
if (app_ctx->misc == NULL) {
perror("malloc failed in algo dup2 init");
exit(EXIT_FAILURE);
}
memset(app_ctx->misc, 0, sizeof(struct dup2_ctx));
}
int algo_dup2_on_stream(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
char url[256];
struct evt_core_fdinfo *to_fdinfo = NULL;
struct algo_ctx* app_ctx = fdinfo->cat->app_ctx;
union abstract_packet *ap = (union abstract_packet*) &bp->ip;
struct dup2_ctx* dup2c = app_ctx->misc;
int32_t id = -1, port = -1;
if (ctx->verbose > 1) {
fprintf(stderr, " [algo_dup2] Received a buffer\n");
dump_buffer_packet(bp);
}
do {
switch (ap->fmt.headers.cmd) {
case CMD_UDP_METADATA_THUNDER:
id = ap->fmt.content.udp_metadata_thunder.id;
break;
case CMD_UDP_ENCAPSULATED:
port = ap->fmt.content.udp_encapsulated.port;
break;
default:
break;
}
} while ((ap = ap_next(ap)) != NULL);
if (ctx->verbose > 1) fprintf(stderr, " [algo_dup2] Extracted port=%d and id=%d\n", port, id);
if (port == -1 || id == -1) {
fprintf(stderr, "Missing data port=%d and id=%d...\n", port, id);
exit(EXIT_FAILURE);
}
// Check that received identifier has not been delivered
if (ring_ge(dup2c->recv_id, id)) {
if (ctx->verbose > 1) fprintf(stderr, " [algo_dup2] Packet already delivered, dropping\n");
mv_buffer_rtof(&app_ctx->br, fdinfo);
return 0;
}
// Update delivered identifier
dup2c->recv_id = id;
// 1. Find destination
sprintf(url, "udp:write:127.0.0.1:%d", port);
to_fdinfo = evt_core_get_from_url (ctx, url);
if (to_fdinfo == NULL) {
fprintf(stderr, "No fd for URL %s in tcp-read. Dropping packet :( \n", url);
mv_buffer_rtof (&app_ctx->br, fdinfo);
return 1;
}
// 2. Move buffer
if (ctx->verbose > 1) fprintf(stderr, " [algo_dup2] Scheduling packet for write\n");
mv_buffer_rtow (&app_ctx->br, fdinfo, to_fdinfo);
main_on_udp_write(ctx, to_fdinfo);
return 0;
}
int algo_dup2_on_datagram(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
struct evt_core_fdinfo *to_fdinfo = NULL;
struct algo_ctx* app_ctx = fdinfo->cat->app_ctx;
struct dup2_ctx* dup2c = app_ctx->misc;
dup2c->emit_id = dup2c->emit_id + 1;
union abstract_packet metadata = {
.fmt.headers.cmd = CMD_UDP_METADATA_THUNDER,
.fmt.headers.size = sizeof(metadata.fmt.headers) + sizeof(metadata.fmt.content.udp_metadata_thunder),
.fmt.headers.flags = 0,
.fmt.content.udp_metadata_thunder.id = dup2c->emit_id
};
buffer_append_ap (bp, &metadata);
if (ctx->verbose > 1) {
dump_buffer_packet(bp);
fprintf(stderr, " [algo_dup2] Added metadata\n");
}
struct evt_core_cat* cat = evt_core_get_from_cat (ctx, "tcp-write");
for (int i = 0; i < app_ctx->ap.links; i++) {
// 1. A whole packet has been read, we will find someone to write it
to_fdinfo = cat->socklist->len > i ? g_array_index(cat->socklist, struct evt_core_fdinfo*, i) : NULL;
if (to_fdinfo == NULL) {
fprintf(stderr, "No fd for cat %s in udp-read.\n", cat->name);
continue;
}
// 2. We move the buffer and notify the target
dup_buffer_tow (&app_ctx->br, bp, to_fdinfo);
main_on_tcp_write(ctx, to_fdinfo);
}
if (ctx->verbose > 1) fprintf(stderr, " [algo_dup2] Packets sent\n");
// 3. Release the buffer
mv_buffer_rtof (&app_ctx->br, fdinfo);
return 0;
}
int algo_dup2_on_err(struct evt_core_ctx *ctx, struct evt_core_fdinfo *fdinfo) {
// We do nothing
return 1;
}